There is a port of MicroPython to RTEMS that was written for the ESA however this is under a non 2BSD or similar license.
Since that port has been written there are two new progessions that will help in a community based effort substantially
An embed port for MicroPython:
and a port to Zephyr released under an Apache 2.0 license:
The Zephyr port will at least show us what we need to do in order to get MicroPython under RTEMS in a useful way.
We currently have this as a project which is open to anyone including GSoC students:
If anyone is interested please feel free to comment here or open new topics with questions.
As far as support: Getting it running as a first step is huge. After this adding support to RTEMS internals and then the specific hardware support such as GPIO for Raspberry Pi or Beagle Bones.